Wow, what is the source of this outrageous claim??

If anything, African states are going to be hit the hardest. South Africa for example, a country I am in, has the world's highest HIV cases. Pneumonia is a death sentence for HIV patients. Also, our infrastructure to manage a spike in infected arriving at state hospitals is abysmal. Right now, we sit with 7 infected (officially) but these are all index based with vectors from recent visits to Italy. If this changes to non-index based vectors, and this disease spreads to the townships, we are done for. If anything, COVID-19 is likely going to hammer Africa the hardest.

Or more likely, the poor of Africa who live in close, unsanitary conditions will be hit incredibly hard because their healthcare system cannot cope

By and large improved health care won't affect population resistance all that much, it just improves survival rate. In an earlier time you would have been right, European germs caused more Native American deaths than Europeans themselves when they first colonized, but nowadays with global trade we all end up sharing the same diseases for the most part.

Sedentary lifestyles enabled by modern lifestyles as opposed to a hunter-gatherer lifestyle can contribute to decreased overall health but thats not the issue here since almost nobody is a hunter-gatherer anymore.

When it comes to new viruses, all of us are in the same boat immunity-wise.

First of all "there is still natural selection" in literally all life, so I think you're meaning something else. But to what your point actually is, do you have any source on that?

I know several people that would have not been able to reach adulthood 100 years ago but have now reproduced and have passed on their diseases to their offspring. There is no doubt that natural selection in humans is much weaker now then in the past.

That's not what natural selection means... medical innovations are still natural selection factors. It doesn't stop, we just naturally figure out how to get better at it.

This was a bit of a poorly-considered comment.

To take you at your intent, all humans will be exposed to this virus with more or less the same chances of suffering. I imagine there may be pockets of resistance within certain gene pools, but it's a crap-shoot who and where.

I'm gussing that the downvotes are because of an implicit link to eugenics and racism.

those liking scifi: Asimov explored the idea in one of his novels. "Spacers" vs "Earthers" in the novel "The Caves of Steel"

This is uninformed speculation.

Why isn't Africa innately resistant to HIV then?